On the cheaper selection of bats I don't think re stickering is viable.
Most stickers leave marks, and the shop itself isn't gonna wanna be there with a heat gun, and glue remover going through a few bats.
The manufacturers won't want them back, mainly cos they've been paid for. But if they hadn't, delivery back to factory, the hours of sticker changing, and removing proof of old stickers.
Far too much hassle and cost than its worth.
As for the higher end bats, well the shops aren't gonna buy a huge amount to start with, so there probably isn't many that need restickering and they'd sell quickly anyway with an Ensor season discount.